To prevent intrusion of insect pests and dust through a door from the outside in an insect and dust proofing facility for a store composed so that a customer enters and exits by opening and closing the door.

A suction fan 3 is provided for introducing outside air into the store 1 via a dust proof filter 2, a detecting means 4 is provided for detecting entrance and exit of the customer to the store 1 by opening and closing of the door 6, and the suction fan 3 is driven and stopped by the detecting means 4.